What should I use for a core?

[Beefer]

The plywood coring of a deck panel has rotted, and I'm finally going to repair it. It's the access for panel to remove the fuel cell, and has 2 pie plates in it. It's like 30" x 54" in. in size. I was going to go with marine plywood, but started thinking if I could use a lighter weight alternative. It's in the middle of the cockpit, and is walked on continuously, so it would need to support considerable weight. Any suggestions that are comparable to the cost of MP?

 

[Woodonglass]

Re: What should I use for a core?

Arauco Plywood when coated with Poly and Mat will last for decades. Sold @ Lowes or Home Depot.

 

[produceguy]

Re: What should I use for a core?

Beefer, will it be covered?
If not ,I like using redwood planks,sanded and with 4 coats of cabot gloss spar varnish , looks sharp if you like wood grain. Thou redwood is very soft and for a area like that might it might need somr extra support. Just a thought.

 

[Beefer]

Re: What should I use for a core?

It's in the open cockpit area, and I don't keep the boat covered. The pie plates will be reinstalled, and I'll have to cut the core to put them in. It looks to e like the factory didn't seal the cuts for the access plates, and over the years (1984), the core just rotted away.

To do the repair, I was going to cut out the old, pour some (polyester) resin, and lay the new core down. Then cover the core with more resin to seal it. This will be my first repair job like this.

 

[Woodonglass]

Re: What should I use for a core?

Poly Resin without mat is useless. It will crack and peel. Epoxy does not require mat, but if you want to gelcoat for a finish, gelcoat will not adhere to epoxy.

 

[Beefer]

Re: What should I use for a core?

It's the underside of the panel, so no gelcoat needed. So I need to use mat, or can I switch to epoxy, and not have to get into the mat etc.? I'm thinking remove the old, cut the new to size, brush on a layer of resin on the new core, pour resin onto the panel, lay the core into that resin, then coat the rest of it. I'm under the impression that the resin will act as an adhesive, keeping the core to the panel. Is that all correct?

 

[Woodonglass]

Re: What should I use for a core?

If you use epoxy, you are correct, not mat or cloth is required. Cloth would make it bullet proof but not required.